26 research outputs found

    First attempted breeding of Manx Shearwater (Puffinus puffinus Brünnich, 1764) on Santa Maria, Azores

    Get PDF
    The Manx Shearwater Puffinus puffinus (Brünnich, 1764) is a north Atlantic seabird which mainly breeds in Europe. In the Azores, its breeding colonies occur exclusively on the islands from the western group (Flores and Corvo). Here, we report the first breeding attempt observed on Vila islet, Santa Maria (the easternmost island of the archipelago, situated circa 600 km from Flores and Corvo). Our observation confirms that Manx Shearwaters can settle far from their usual breeding localities and enhances the importance of Vila islet for the Azorean marine avifauna

    Metabarcoding, stables isotopes, and tracking: unraveling the trophic ecology of a winter-breeding storm petrel (Hydrobates castro) with a multimethod approach

    Get PDF
    Detailed information on diet and foraging ecology is scarce for most small seabirds such as storm petrels. In this study, we used molecular techniques, stable isotope analysis, and geolocators to study the diet, trophic ecology, and at-sea distribution of Madeiran storm petrels (Hydrobates castro) breeding in Farilhoes Islet, Portugal, in 2015-2017. The diet of Madeiran storm petrels was dominated by fish for both sexes and study years, with Gadidae representing the main prey family. In 2017, females also fed on Aulopiformes, Stomiiformes and Myctophiformes, which were not identified in the other groups, suggesting some degree of inter-annual and intersexual plasticity in their diet. The carbon isotopic ratios of birds during 2017 were significantly higher when compared to 2015, which might be related to foraging near coastal areas in 2017. Indeed, tracking data for 2017 show that birds foraged near the colony and near the West African coast. Overall, both sexes of this species exhibited a similar trophic ecology and diet during the breeding season. However, intersexual differences occurred during the non-breeding season, when females showed significantly lower nitrogen isotopic ratios than males (in 2016), and the lowest niche overlap between sexes occurred. This, together with the fact that environmental conditions appeared less favourable in 2016 suggests that intersexual differences in the foraging ecology of this species may be related with environmental conditions

    Global assessment of marine plastic exposure risk for oceanic birds

    Get PDF
    Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

    Global assessment of marine plastic exposure risk for oceanic birds

    Get PDF
    Plastic pollution is distributed patchily around the world’s oceans. Likewise, marine organisms that are vulnerable to plastic ingestion or entanglement have uneven distributions. Understanding where wildlife encounters plastic is crucial for targeting research and mitigation. Oceanic seabirds, particularly petrels, frequently ingest plastic, are highly threatened, and cover vast distances during foraging and migration. However, the spatial overlap between petrels and plastics is poorly understood. Here we combine marine plastic density estimates with individual movement data for 7137 birds of 77 petrel species to estimate relative exposure risk. We identify high exposure risk areas in the Mediterranean and Black seas, and the northeast Pacific, northwest Pacific, South Atlantic and southwest Indian oceans. Plastic exposure risk varies greatly among species and populations, and between breeding and non-breeding seasons. Exposure risk is disproportionately high for Threatened species. Outside the Mediterranean and Black seas, exposure risk is highest in the high seas and Exclusive Economic Zones (EEZs) of the USA, Japan, and the UK. Birds generally had higher plastic exposure risk outside the EEZ of the country where they breed. We identify conservation and research priorities, and highlight that international collaboration is key to addressing the impacts of marine plastic on wide-ranging species

    Data from: Nest fidelity is driven by multi-scale information in a long-lived seabird

    No full text
    Although the reproductive success of most organisms depends on factors acting at several spatial scales, little is known about how organisms are able to synthesize multi-scale information to optimize reproduction. Using longitudinal data from a long-lived seabird, Monteiro's storm-petrel, we show that average breeding success is strongly related to oceanic conditions at the population level, and we postulate that (i) individuals use proximal information (their own reproduction outcome in year t) to assess the qualities of their mate and nest and to decide to retain them or not in year t + 1; (ii) the intensity of these responses depends on the quality of the oceanic environment in year t, which affects the predictability of reproduction outcome in year t + 1. Our results confirm that mate and nest fidelities are higher following successful reproduction and that the relationship between the success of a given pair and subsequent nest fidelity is stronger in years with unfavourable oceanic conditions, suggesting that individuals rely on distant information to modulate their use of proximal information and adjust their breeding strategy

    Environmentally driven sexual segregation in a marine top predator

    No full text
    Sexual segregation in foraging occurs in many animal species, resulting in the partitioning of resources and reduction of competition between males and females, yet the patterns and drivers of such segregation are still poorly understood. We studied the foraging movements (GPS-tracking), habitat use (habitat modelling) and trophic ecology (stable isotope analysis) of female and male Cory's shearwaters Calonectris borealis during the mid chick-rearing period of six consecutive breeding seasons (2010-2015). We found a clear sexual segregation in foraging in years of greater environmental stochasticity, likely years of lower food availability. When food became scarce, females undertook much longer foraging trips, exploited more homogeneous water masses, had a larger isotopic niche, fed on lower trophic level prey and exhibited a lower body condition, when compared to males. Sexual competition for trophic resources may be stronger when environmental conditions are poor. A greater foraging success of one sex may result in differential body condition of pair mates when enduring parental effort, and ultimately, in an increased probability of breeding failure

    Influence of environmental factors and energetic value of food on Little Tern Sterna albifrons chick growth and food delivery: Capsule Chick diet and early growth parameters differed between birds breeding on natural (sandy beaches) and alternative (salinas) habitats

    No full text
    Aims To describe diet and growth of Little Tern chicks, to examine the influence of tide and wind speed on food delivered to chicks in southern Portugal, and to determine whether diet and early chick growth parameters differed between birds breeding in natural (sandy beaches) and man-made alternative (salinas) habitats. Methods Nests were marked and visited regularly. Chicks were ringed and weighed at hatching. Between 12 and 14 nests were enclosed by a fence in order to measure and weigh chicks every day. Prey items delivered to fenced chicks were observed daily from hides, in different tidal periods and wind speed conditions. Prey items dropped in the colonies were collected. Foraging efficiency of adults was evaluated in relation to tide and wind speed. Fresh prey items were collected to determine their energetic content using a calorimeter. Results A chicks grew faster than B chicks, but both attained the same weight, tarsus-length and wing-length at 19 days old; C chicks attained the same values at day 21. There were significant differences in early growth parameters. A and B chicks grew faster on sandy beaches than on salinas. The main prey items were Atherina spp., Fundulus sp. and shrimps in salinas and Sardina pilchardus, Atherina spp. and Belone belone on sandy beaches. There was no correlation between ingestion rate and chick age, but mean length of prey ingested by chicks increased significantly with age. Conclusion Tide and wind speed influenced both size and type of prey delivered to chicks. Parents met the increasing energy demands of the growing chicks by adjusting prey size rather than prey delivery frequency. Differences in chick growth between salinas and sandy beaches could be related to both parental quality and diet. The presence of a high energy-content euryhaline fish species in the salinas, together with more sheltered conditions and no tidal influences, may be important in explaining the use of salinas by Little Terns
    corecore